Abstract

   In this paper we define the quantum version of the Tsallis entropy in terms of quantum phase space distribution functions. The quantum Tsallis entropy is compared with Kenfack’s nonclassicality indicator, for different systems, such as the Schr ̈ dinger cat state, the thermal state, a superposition of the ground and the first excited                           o number states, and the harmonic oscillator state. These comparisons indicate that the Wigner representation gives us complete information about the state with the nonextensivity parameter q = 1, while the Husimi representation hides some information with the nonextensivity parameter q < 1.